Hives are a skin rash that can be triggered by a reaction to food, medicine or other irritants. They can appear in various skin welt patterns. These welts often itch and vary in size. Often, they go away in 24 hours, but if they continue to persist, please make an appointment with our Board Certified Dermatologist for a proper diagnosis. If your hives are accompanied by throat swelling, difficulty breathing, itchy throat, swollen lips, or a severe rash, call 911 and head to an emergency room immediately.